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Top Cybersecurity companies in the United States

Companies defending or attacking software, networks, and cloud infrastructure. Filtered to companies headquartered in the United States.

Built from a search like: “Top Cybersecurity companies in the United States”

Ranked by current headcount across Cybersecurity companies headquartered in the United States. Refreshed daily.

  1. 1
    Palo Alto Networks· Santa Clara, California, United States
    • Series C
    • 21.4k employees
    • Founded 2005
  2. 2
    Fortinet· Sunnyvale, California, United States
    • Series B
    • 16k employees
    • Founded 2014
  3. 3
    CrowdStrike· Remote, Oregon, United States
    • Post-IPO equity
    • 11.3k employees
    • Founded 2011
  4. 4
    Zscaler· San Jose, California, United States
    • Post-IPO debt
    • 9.6k employees
    • Founded 2008
  5. 5
    Own Company· Englewood Cliffs, New Jersey, United States
    • Series E
    • 8.5k employees
    • Founded 2012
  6. 6
    Check Point Software· Redwood City, California, United States
    • Post-IPO debt
    • 8.4k employees
    • Founded 1993
  7. 7
    Cloudflare· San Francisco, California, United States
    • Post-IPO debt
    • 6.9k employees
    • Founded 2009
  8. 8
    HackerOne· San Francisco, California, United States
    • Series unknown
    • 6.6k employees
    • Founded 2012
  9. 9
    McAfee· Sunnyvale, California, United States
    • Private equity
    • 5.6k employees
  10. 10
    Proofpoint· Sunnyvale, California, United States
    • Post-IPO debt
    • 5k employees
    • Founded 2002
  11. 11
    Trellix· Plano, Texas, United States
    • 3.9k employees
    • Founded 2022
  12. 12
    Bugcrowd· San Francisco, California, United States
    • Debt
    • 3.6k employees
    • Founded 2012
  13. 13
    Qualys· San Mateo, California, United States
    • Series C
    • 3.6k employees
    • Founded 1999
  14. 14
    Arctic Wolf· Eden Prairie, Minnesota, United States
    • Convertible note
    • 3.4k employees
    • Founded 2012
  15. 15
    Netskope· Santa Clara, California, United States
    • Series unknown
    • 3.3k employees
    • Founded 2012
  16. 16
    Rapid7· Boston, Massachusetts, United States
    • Post-IPO equity
    • 3.3k employees
    • Founded 2000
  17. 17
    Wiz· New York, New York, United States
    • Series unknown
    • 3.3k employees
    • Founded 2020
  18. 18
    SentinelOne· Mountain View, California, United States
    • Post-IPO equity
    • 3.2k employees
    • Founded 2013
  19. 19
    Infoblox· Santa Clara, California, United States
    • Private equity
    • 3k employees
    • Founded 1999
  20. 20
    RSA Security· Burlington, Massachusetts, United States
    • Debt
    • 2.7k employees
    • Founded 1982
  21. 21
    AMI· Duluth, Georgia, United States
    • Private equity
    • 2.6k employees
    • Founded 1985
  22. 22
    KnowBe4· Clearwater, Florida, United States
    • Debt
    • 2.4k employees
    • Founded 2010
  23. 23
    Optiv· Denver, Colorado, United States
    • Debt
    • 2.4k employees
    • Founded 2015
  24. 24
    Tenable· Columbia, Maryland, United States
    • Post-IPO equity
    • 2.3k employees
    • Founded 2002
  25. 25
    Tanium· Kirkland, Washington, United States
    • Secondary
    • 2.3k employees
    • Founded 2007

Find engineers at Cybersecurity companies in the United States

the United States has long been a hub for Cybersecurity, and the list above ranks the largest Cybersecurity companies headquartered there by current headcount, drawn from public LinkedIn and Crunchbase records. With 2,813 matching companies in our index, this is a good map of where the Cybersecurity talent in the United Stateslives — useful whether you’re recruiting, partnering, or sizing a market.

The biggest Cybersecurity companies in the United States tend to be the gravitational centres for specialised talent — senior engineers, ML researchers, applied scientists, designers — while the smaller ones compete on speed, equity, and proximity to founders.

Refolk converts this list into a live search. Ask for “Cybersecurity engineers in the United Stateshiring senior staff” or “founders of Cybersecurity companies in the United Stateswho left in the last 12 months” and Refolk returns a ranked shortlist with the evidence that earned each person a spot.

How this list is built

Refolk pulled Cybersecurity companies headquartered in the United States from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 10 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 06:55:22 GMT

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